Don't lift cast nodes out into let statements
Don't lift cast nodes out into let statements

It breaks peephole matching that assumes cast nodes will be in place.


Former-commit-id: 533db2aef454c1f4f8ee72492bf106d6d8ebd401
darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide